Successive interference cancellation for multiuser asynchronousDS/CDMA detectors in multipath fading links

There has been an increasing interest in the use of code-division multiple access (CDMA) in cellular mobile and wireless personal communications. The choice of such multiaccess technique is attractive because of its potential capacity increases and other technical factors such as privacy and multipath rejection capabilities. However, it is well known that the performance of CDMA can be significantly degraded due to cochannel interference (CI) and the near-far effects. We consider the performance of direct-sequence (DS)-based CDMA over fading channels that are modeled as slowly varying Rayleigh-fading discrete multipath channels. Specifically, we propose and analyze an adaptive multistage interference cancellation strategy for the demodulation of asynchronous DS spread-spectrum multiple-access signals. Numerical results show that the proposed multistage detector, which alleviates the detrimental effects of the near-far problem, can significantly improve the system performance     

实行全面质量管理 做好江口水电站工程设计

江口水电站是芙蓉江干流开发中的骨干工程。为认真履行江口工程的设计合同，确保优质、高效地完成江口工程的各项设计工作，长江委设计院实行全面质量管理，建立了一套规范化的统计管理程序，制订详细的设计计划，落实江口工程项目各级责任人的质量责任制，采取特殊技术措施，对工程设计过程中的各项质量活动进行全过程的管理，使江口工程在满足质量标准、合同进度的情况下，工程投资最省。     

彩色PDP用玻璃基板

本文讨论了彩色ＰＤＰ现用钠钙玻璃的热稳定性，指出由于这种玻璃在热处理过程中易变形和收缩，因而不适合作大面积彩色ＰＤＰ基板材料，介绍了彩色ＰＤＰ基板玻璃的制造方法和特点。最后介绍了日本旭硝子公司和美国康宁公司各自为彩色ＰＤＰ新开发的玻璃基板材料ＰＤ２００和ＣＳ２５。     

晶须取向对SiCw／Al复合材料切削表面质量的影响

切削与晶须取向方向间的夹角对ＳｉＣｗ／Ａｌ复合材料切削表面质量有很大影响。当切削角为４５°时，晶须拔出和转动现象均较少，复合材料切削表面粗糙度最低。当切削角为１３５度时，晶段转动造成的撕裂破坏程度很大，复合材料切削表面粗糙度最大。     

微量Ag对CP276合金性能和组织的影响

研究添加不同含量的Ａｇ对ＣＰ２７６合金的拉伸性能和时效组织的影响。对拉伸强度、延伸率测试及透射电镜观察表明：０．１１ｗｔ％加入可促进Ｔ１相析出，使合金强度值升高；０．３５ｗｔ％Ａｇ的加入可在时效前期生成富Ａｇ、Ｍｇ的稳定的ＧＰ区，从而降低合金中Ｃｕ的固溶度，阻碍Ｔ１相析出，时效后期，ＧＰ区分解，生成大量Ｔ１相，使合金强度值显著升高。     

基于CAN总线的汽车测试解决方案

更高功能的汽车设计带动更复杂的汽车电子测试技术的发展。中国的汽车测试界尤其面对着设备的短缺、技术的匮乏等诸多困难。本文针对中国的汽车电子测试业。介绍了一种集成的软硬件同步平台。它基于CAN总线领域中的PXI总线。及国际广泛应用的测试管理TestStand软件。构建成高集成度、可靠性、升级维护方便、开放彻底的测试系统。     

Investigation of texture effect on visual colour difference evaluation

The texture effect on visual colour difference evaluation was investigated in this study. Five colour centers were selected and textured colour pairs were generated using scanned textile woven fabrics and colour‐mapping technique. The textured and solid colour pairs were then displayed on a characterized cathode ray tube (CRT) monitor for colour difference evaluation. The colour difference values for the pairs with texture patterns are equal to 5.0 CIELAB units in lightness direction. The texture level was represented by the half‐width of histogram, which is called texture strength in this study. High correlation was found between texture strength and visual colour difference for textured colour pairs, which indicates that an increasing of 10 units of texture strength in luminance would cause a decreasing of 0.25 units visual difference for the five colour centers. The ratio of visual difference between textured and solid colour pairs also indicates a high parametric effect of texture. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 341–347, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.     

知识驱动的UG中的产品开发

重点论述了UG中的KBE即KF模块的知识驱动产品开发设计过程及其关键技术，介绍了知识驱动自动化过程，实例剖析了UG中的KF在产品开发设计过程中的应用。     

Cooperative Effect Radiation Loss of Optical Pump Solid Laser

1 Introduction For increasing the output energy of laser, the pumping power must be enhanced. But the cooperative effect will arise and cause spontaneous radiation light in laser medium sample when the pumping power is high e- nough without the resonator. The spontaneous radiation light is coherent light between laser and fluorescent. It will compete the upper energy level population with ex- cited radiation, and the loss increase. In solid laser medium, such as Nd∶YAG, the Nd ion densityi…